Alternating-current rectifier.



Patented Ju 10,1913.

DONALD ivi. Brass, or- WEST cannon, NEW JERSEY, nssicivon TorrnoMAs A.Enrsou, iivoonroen'rnn, or WEST ORANGE, NEW JE'nsEY, A'conPonArrioN OFNEW JERSEY.

ALTERNATING-CURR'ENTRECTIFIER.

Specification of LettersfPatent. I Patgnt gd lung 10, 1913',

Application filedAugust.-21 ,'1911. Serial noqeiaies.

To aZZ whom it mag concern:

Be it known that I, DonAUYM. BLISS,'2L subject of the King of GreatBritain, and aresident of West Orange,"in the county of Essex and StateofNew Jersey, have invented certain new and useful Improvements inAlternating-Current Rectifiers, of which the following is aspecification. i i y In In I applications Serial N 0. 584,089, filedSeptember 27 1910, and Serial No. 645,164, filed on even date herewith,I have described and claimed a rectifying system in which two-partrectifying switches, each provided with its own set of brushes, arearranged in series in such a manner that the connection leading from thealternating current supply circuit to the direct current work circuit isbroken simultaneously at a plurality o fpoints, so as to minimizesparking.

My present invention comprises an im-. provement on the inventionsdescribed and claimed broadly in the aforesaid applications and consistsin simple and eificient.

means for rectifying alternating current for any urpose, as, forexample, chargingstorage atteries, and combines the advantages of aseriesfifbreaks .or gaps with that of a single rotating commutator orswitch, where-' by the expense of construction is reduced, and thedeviceis renderedmore compact and efficient. I

Myinvention consists also in the combinations and detailsot constructionhereinafter described and claimed.

In the accompanying drawings which form a part ofthis specification, andin which like reference characters are used to designate like partsthroughout the several views-eliigure 1 is diagrammatic view showing anembodiment of my invention adapted to utilize alternate halfway es ofalternating current; and Fig. 2 is a diagrammatic view of anotherembodiment of my invention adapted to utilize both half waves ofalte'rnatingcur'rnt.

Referring to Fig. 1 of the drawings, al-- ternating current mains areshown at l and 2, and are fed from any convenient source withalternating current to be rectified.

improved rectifying device is connected in a circuit 3, 4:,acros's thealternating current mains 1 and 2, and the said circuit 8, 4 con' tainsa direct current translating device, as for example, a battery 5, towhich the rect1- fied current is tobe supplied. My improved rectifyingdevice comprises active segments 6, 7," 8 andj9 of conducting material,and

dead sections 10, 11, 12 and 13. The dead sections serve to insulate theactive segments from each other, and may consist of single pieces ofinsulating material, but are preferably constructed of segments of thesame, conducting material as the active segments, the said segmentsbeing separated from each other by means of insulating material, such asmica The advantage of this'construction is that the commutating deviceWears down uniformly over all of its surface. 50p- -positely dispo edactive segments 6 and 8 are connected y a conductor 14, and oppos'itelydisposed segments-7 and 9 areconnected by a conductor 15. Brushes 16,T17, 18 and 19, equal in number to the number of active segments, areprovided for the rectify'.

ing device, and symmetrically disposed around the same and adaptedtocontact withthe active segments. Brushes .17 and 18 are connected by aconductor20, and the 22 and 23 and connected to the .commut'ating devicein any suitable manner, asby a shaft 21, may beemployed for thispurpose. I have illustrated a commutating device containing four activesegments, and the proper speed for such a device corresponds to that ofan eight-pole synchronous motor. In

general, if the commutatin-g device is operated at the same speed as themotor, the num- 'ber of active segments and the number of brushes areeach equal to half thenumber of poles of the motor. Obviously, gear ngmay be interposed between the commutating device and the synchronousmotor, and if the speed ratio is changed by 'spch gearing,

segments and the number of poles of the motor willbe altered. Theposition of the rectifying device-and brushes shown in thisfigurecorresponds to the crest of one of the half waves ofthealternatingcurrentgto be,

the relation between the number of act 've ll05 rectified, and the pathof the current may be traced as follows: from the alternating currentmain 2, through conductor 4, brush 19, active segment 9,'conductor 15,active segment '2, brush 17, conductor 20, brush 18, active segment 8,conductor 14, active segment 6, brush 16, through the battery or directcurrent translating device 5, and conductor 3', to the alternatingcurrent main 1. This circuit is kept. closed substantially throughoutthis half wave. During the next half wave; circuit is broken, and duringthe succeeding half wave it is reestablished, and so on indefinitely. inthis form of appa-- ratus, only alternate half waves of alternatingcurrent are utilized. M

Tn 2 T have illustrated a modification of the structure shown in Fig. 1,and in which both half waves of the alternating current are utilized. Inthis figure, as in Fig. 1, the alternating current mains are shown at 1and 2, the direct current translating device or battery at '5, and thesynchronous motor at 21, connected to the alternating current mains 1and 2 by the con ductors 22 a'nd 23. The rectifying or com- ,mutatingdevice comprises active segments '30, 31, 32 and 33 of conductinmaterial, and dead sections 34, 35, 36 and 37. The dead sections serveto insulate the active segments from each other and consist preferablyof conduct-mg sections of the same material as the active segments, andinsulated from each other by any suitable material, such as mica. Theoppositely disposed active segments 30 and 32 are connected by conductor34 and the oppositely disposed active segments 31 and 33 are connectedby the conductor 35. Brushes 38, 39, v40, 41, 42, 43, 44 and 45 aresymmetrically arranged around the commutating or rectifying device andare adapted 'to contact with the segments thereof. In this modificationthe number of brushes is twice the number of active segments. Thebrushes 38 and 39 are connected to one of the alternating current mains1 in any suitable manner, as by conductors 46 and 47, and the brushes 40and 45 are connected to the other alternating current main 2 by anysuitable means, as by conductors 48 and 49. The brushes 41 and 42 areconnected to one terminal of the battery 5, as by conductors 50 and 51,and the brushes 43 and 44 are connected to the other terminal of thebattery as by conductors 52 and 53. An adjustable reactance 54 ma beinserted in the direct current work circuit for the purpose of smoothingcut the rectified current, and also for controlling the phase relationof the current impulses relative to the electro-motive force. In thearrangement of apparatus illustrated in Fig. 2, an eight-polesynchronous motor is employed for driving the rectifying commutator insynchronism with path of the current at this instant may be traced asfollows :'from the alternating current main 2 through the conductor 43,brush 40, active segment 31, conductor 35, active segment 33,'brush 44,conductor 53,

. reactance 54, battery 5, conductor 51, brush 42, conductor 34, activesegment 30, brush 38, conductor 47, to the alternating current main 1.This connection is kept closed substantially throughout one half wave ofthe alternating current. During the succeeding half wave, the path ofthe current may be traced as follows :from the alternating current main1, through the conductors 47 and 46, brush 39, active segment 30,conductor 34, active segment 32, brush 43, conductor 52, reactance 54,battery 5, conductor 50, brush 41, active segment 31, conductor 35,active segment 33, brush 45, conductor 49, to the alternating currentmain 2. It is apparent that bothhalf wavesv of the alternating currentare utilized in this form of my invention.

In each of the modifications, a number of breaks in series in thecircuit occur simultaneously each time a set of brushes passes from aset of aciive segments. in the specific forms illustrated, there arefour such series breaks. Obviously, the number of breaks may beincreased by increasing the number of active segments. the number ofactive segments may be increased to six, eight, twelve, or more.

. Having now described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is as follows L 1. In analternating current rectifying system, a commutator having a pluralityof her example,

insulated pairs of electrically connected ac-' tive segments, and a setof brushes common to all of said segments, half of which are arrangcdtobe connected in series during alternate half waves of alternatingcurrent, and the other half of which are arranged to be connected inseries during the other half waves of alternating current,-substantiallyas described,

2. In an alternating current rectifying system, alternating currentmains, a direct current translating device, a plurality of brushes, anda commutator for connecting the direct current translating device to thealternating current mains alternately through each half of the brushes,said commutator having conducting" segments, all of which are adapted tocooperate with each of said brushes, substantially as described.

3. Tn an alternating current rectifying system, alternating currentmains, a direct current translating device, a plurality of' brushes, anda commutator for connecting the direct current translating device to thealternating current mains through each half of the brushes, the saidcommutator having active segments adapted to contact with each of saidbrushes succes sively, substantially as described.

4. In an alternating current rectifier, a plurality of insulated pairsof oppositely disposed and electrically connected active segmentssymmetrically disposed and mounted for rotation around an axis, a set ofbrushes symmetrically disposed around said axis and located to contactWith each of said segments during-a portion of the rotative movementthereof, and means enabling said brushes to be connected in seriesthrough all. of said segments While said brushes and segments are incontact, substantially as described.

5. In an alternating current rectifier, a plurality of insulated pairsof oppositely disposed and electrically connected active segments, saidsegments being symmetrically disposed and mounted for rotation aroundalternatelyan axis, and a set of brushes,,the number of the rotativemovement thereof, substantially as described.

6'. In an alternating current rectifier, a plurality of oppositelydisposed and electrically connectedpairs of active conducting segments,having contact surfaces lying in a cylindrical surface, and deadsections of the same material as the active segments located betweenadjacent active segments and insulated therefrom, said dead sectionshaving contact surfaces lying in the same cylindrical surface as thecontact surfaces of the active segments, substantially as described.

-This specification signed and witnessed this'18th day of August 1911.

DONALD BLISS.

Witnesses i 1 HENRY LANAHAN, ANNA R. KLEHM.

